Sounds like mine except you have the stick model.
Just to note, most of the driving is more or less ideal, not many stops and an hour drive each way to work. Under the hood there is a sticker that says what engine size the car came with factory. If I remember right, the DX only came in a 1.8L. I got about the same miles too at 260k
.
My 2nd O2 sensor has been flagging my cat being bad since winter, so maybe the increased back pressure of a plugged cat is helping my mpg. I'll Probably have to install a straight pipe and deal with the check engine light before this next winter.
Anyway, good luck with your corolla
.